JTree tree1=new JTree();
//.......添加节点
add(new ScrollPane(tree1)

DefaultMutableTreeNode root=new DefaultMutableTreeNode("dongxi")//后面的是备注
DefaultMutableTreeNode root=new DefaultMutableTreeNode(new Good("aa",11));//还可以作为叶子new 对象

addTreeSelectionListener(TreeSelectionListener listener)

public void valueChanged(TreeSelectionEvent e)

DefaultMutableTreeNode node1=(DefaultMutableTreeNode)tree.getLastSelectedPathComponent();//只有树Tree才能用的方法
if(node.isLeaf())//判断是否叶子节点
Obeject a=(Obeject)node.getUserObject()//返回叶子里面的对象

public class test{

    public static void main(String args[]){
        MyWin window1=new MyWin();
        window1.setBounds(12,12,400,300);
    }
}

class MyWin extends JFrame implements TreeSelectionListener{
    JTextField text1;
    JButton button1,button2;
    JTextArea textArea1,textArea2;
    JLabel label1;
    JTree tree1;
    MyWin(){
        init();
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    void init(){
        DefaultMutableTreeNode root=new DefaultMutableTreeNode("Goods");
        DefaultMutableTreeNode nodeTV=new DefaultMutableTreeNode("TV");        
        DefaultMutableTreeNode nodePhone=new DefaultMutableTreeNode("phone");    
        DefaultMutableTreeNode tv1=new DefaultMutableTreeNode(new Goods("huangTV",11));
        DefaultMutableTreeNode tv2=new DefaultMutableTreeNode(new Goods("yuTV",21));
        DefaultMutableTreeNode phone1=new DefaultMutableTreeNode(new Goods("ga",31));
        DefaultMutableTreeNode phone2=new DefaultMutableTreeNode(new Goods("bing",11));
        root.add(nodeTV);
        root.add(nodePhone);
        nodeTV.add(tv1);
        nodeTV.add(tv2);
        nodePhone.add(phone1);
        nodePhone.add(phone2);
        tree1=new JTree(root);
        tree1.addTreeSelectionListener(this);
        setLayout(new GridLayout(1,2));
        add(new JScrollPane(tree1));
        textArea2=new JTextArea(15,15);
        add(new JScrollPane(textArea2));
    }
    public void valueChanged(TreeSelectionEvent e){
        DefaultMutableTreeNode a=(DefaultMutableTreeNode)tree1.getLastSelectedPathComponent();
        if(a.isLeaf()){//是叶子节点？
            Goods b=(Goods)a.getUserObject();
            textArea2.append(b.name+": "+b.price+"\n");
        }
        else
            textArea2.setText(null);
    }
}

class Goods{
    String name;
    double price;
    Goods(String name,double price){
        this.name=name;
        this.price=price;
    }
}